1. Field of the Invention
The present invention relates to a medical or industrial endoscope.
2. Description of the Related Art
Conventionally, endoscopes configured by including an elongated tubular-shaped insertion section are widely used in medical and industrial fields, for example. Among such endoscopes, a medical endoscope used in the medical field is configured to allow observation of an organ or the like by having the insertion section inserted into a body cavity of a subject, such as a living body, and to allow various treatments to be performed on the organ or the like as necessary by use of a treatment instrument inserted in a treatment instrument insertion channel of the endoscope. Furthermore, an industrial endoscope used in the industrial field is configured to allow insertion of the insertion section into an object such as a device or mechanical equipment, such as a jet engine or factory pipes, and to allow observation of a state, such as a state of a flaw or corrosion, inside the object, inspection or the like.
Such a conventional endoscope includes means for radiating illumination light from a distal end portion of the insertion section inserted into a subject, toward an observation target object. Such illumination means is configured by including a light guide fiber bundle which is a light guide member for guiding illumination light emitted by an illumination device through the insertion section and to the distal end portion of the insertion section, and an illumination optical system for emitting the illumination light guided by the light guide fiber bundle from the distal end portion of the insertion section and toward the observation target object, for example. In such a case, the light guide fiber bundle adopts a structure according to which an outer surface of the light guide fiber bundle is covered by a tubular member, for example.
With an endoscope having such a configuration, various alterations are made to efficiently arrange the light guide fiber bundle in an inner space of the distal end portion, and to prevent an outer diameter of the distal end portion of the endoscope from being increased. Various techniques such as molding of the light guide fiber bundle, which is inserted into the insertion section, to have a cross-sectional shape other than a simple circular shape are proposed, for example, by Japanese Patent No. 5112575.
With an endoscope disclosed in Japanese Patent No. 5112575, for example, a cover tube is molded at the same time when molding a distal end part of the light guide fiber bundle such that the cover tube and the distal end part of the light guide fiber bundle are molded to have a substantially same shape.